How much of an alloy that is 10 percent copper should be mixed with 500 ounces of an alloy that is 90?

Tobias gold sells computers at the office center he's guaranteed a minimum salary of $1,959 per month plus 6.3% commission on total sales how much in total sales is he

Given that the images represent 4 steps in the construction of a line segment congruent to a given line segment, which is step 3 in the construction?

How do you figure out which order to do two step equations in? like which thing do you subtract/add/multiply/divide first? i understand that you do the opposite of whatever's shown on the opposite side, but when?